Grit separator



NOV. 12, 1935. Q NORDELL I 2,020,617

GRI T SEPARATOR Filed Feb. 20, 1934 2 Sheets-Sheet 1 1935. c. H. NAORDELL 2,020,517

GRIT SEPARATOR Filed Feb. 20, 1954 2 Sheets-Sheet 2 /8 27 I 4 27 d Inf 36 awe/Wm CARL H Nam .7541.

Patented Nov. 12, 1935 PATENT OFFICE GRIT SEPARATOR Carl H. Nordell, Chicago, 111., assignor to Lakeside Engineering Corporation, Chicago, Ill.

Application February 20, 1934, Serial No. 712,143

11 Claims.

This invention relates to a grit separator and has for its principal object the provision of a device of this character which will continuously, uniformly, rapidly, and efficiently remove all grit 5for solid materials from a flowing solution irrespective of the amount or velocity of the infiuent. It is more particularly designed for removing metals, rocks, sand, grit, etc. from sewage before passing the same to the pumps and other treat- 1o'; ments. 7

Another object of the invention is to eliminate all supports or other obstructions from within the solution so that there will be no opportunity for floating debris to catch and collect.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawings which forms a part hereof. Like numerals refer tolike parts in all views of the drawings and throughout the description.

In the drawings:

Fig. 1 is a plan view, partially broken away, illustrating the improved grit remover.

Fig. 2 is a cross section therethrough, taken on the line 2-2, Fig. 1.

Fig. 3 is a detail section of the bearing thereof.

Fig. 4 is a detail section illustrating the paddle supporting and locking device.

The invention is employed in a cylindrical tank or basin. This may be a metal tank or any 351, other suitablecontainer. It is preferred to install it in a circular concrete basin such as illustrated at In, having an open top and an inclined or conical bottom in which a sump or settling chamber H is formed. An influent passage [2 opens through the side of the basin I and an effluent passage 35 terminates at the side thereof. An efiiuent conduit l3 extends from the wall of the chamber II to the passage 35.

At each side of the basin I0, is a concrete pier l4. I-beams l5 extend over the tank between the piers l4. These beams support a baffle drum I6 within the tank.

The drum I6 consists of a sheet metal cylinder, suitably stiffened and open at its top and bottom.

It is supported from a series of spokes l! extending from hub flanges l8 formed upon a tubular shaft 19. The shaft I9 is supported on a thrust bearing and is guided by a suitable guide bear- 5'5? ing 2| so that it will maintain a rigid vertical position and support the weight of the baflle drum IS.

The drum may be rotated in any desired manner. It is preferred, however, to drive it from an electric motor 22 through a suitable speed re- 5 ducer 23. The shaft 24 of the speed reducer drives the tubular shaft I 9 through a suitable flexible coupling. It is preferred to employ a coupling as shown in Fig. 3, in which radial projections 25 extend outwardly from the speed 1 reducer shaft and contact with suitable stud bolts 26 extending upwardly from the tubular shaft l9.

This construction provides a very flexible connection and also acts as a safety device should 15 the drum become jammed so that it could not rotate. In such a case, the stud bolts 26 will be bent or broken and can be easily renewed. It also accommodates for any settling or mis-alignment of the motor supports.

A series of bracket members 21 extend outwardly beyond the periphery of the drum l6, and adjustably support a series of vertical paddles 28 upon the exterior of the drum. These paddles have a length substantially equal to the height 25 of the drum l6 and a width of slightly less than space between the drum and the basin wall. They are adjustably clamped to the bracket members 21 by means of clamping nuts 36 so that they may be set at any desired angle.

- An efiluent tube 29 projects axially upward within the drum and terminates in a funnelshaped top 30. The tube 29 is supported from an elbow 3| extending from and communicating with the discharge conduit 13. A concave sump plate 32 surrounds the tube 29 in spaced relation therefrom. The plate 32 rests upon the edge of the settling chamber II and forms a continuation of the conical bottom of the basin I0 over the chamber l I.

A grit drawoff pipe 33 extends into the chamber ll terminating in a downwardly extending suction cone 34 adjacent the bottom.

Operation The drum is preferably rotated at a speed to give the paddles 28 a lineal velocity of from 1.25 to 2.5 ft. per second.

The infiuent flows into the basin 10 from the passage I2 and against the bailie drum; then around and beneath the drum to the hopper top 30 of the effluent tube 29, thence through the discharge conduit I3 to the effluent passage 35.

It is well known that the settling of solids from liquids depends upon the velocity of flow of the 55.

liquid. High velocities will keep relatively large particles in suspension while low velocities will drop relatively small particles. Therefore machines which depend. upon the amount of influent, which is always variable, for the velocity cannot give uniform separation results.

Inthe present machine a high velocity inflow will be immediately retarded by the baffle drum to a circular velocity equal to the speed and action of the paddles 28. A low velocity inflow will be immediately increased by the action of the paddles. Therefore, the circular velocity in the race between the drum and the chamber wall will be substantially constant regardless of the amount of inflow. The speed at this point can be brought to the desired point by providing the proper motor speed and by changing the angle of the paddles. Naturally, if the paddles present the surfaces flat to the solution, that is at right angles to the direction of rotation, they will have a greater action than when presented more or less edgewise thereto.

As a result of this predetermined speed, the

coarse and heavy particles will settle to the conical bottom of the basin and will be carried by the vortex action or centripetal force of the revolving solution toward the opening in the plate 32. They will then settle to the bottom of the chamber i i from whence they can be removed by suction through the grit pipe 33.

' Owing to the circular motion of the solution in the race betwten the baffle and basin walls, the fluid flowing beneath the baille drum will enter the center zone on tangential paths so that a similar predetermined vortex action will be maintained within the baffle.

It is desired to call attention to the fact that all braces and supports for the baflle drum iii are positioned above the solution level in the basin lil so that floating debris has no opportunity to catch and collect.

A circular sump plate 32 allows an adjustment to be made, after the concrete installation, so as to obtain the best separation results. The basin H can be cast to give the best structural proportions, then various sump plates 32 can be installed to give the best separation results. If it is found that too much non-grit is being dropped into the chamber l i, the plate 32 can be replaced with a smaller central opening and vice versa.

It is desired to call attention to the fact that there is no necessity for stopping the machine to remove grit as in the usual settling chambers.

The grit may be constantly and simultaneously removed during the separating operation.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention. 7

Having thus described the invention, what is claimed and desired secured by Letters Patent 1. A device for separating grit from solutions comprising: a circular basin; a settling chamber at the center of the bottom of said basin; means for supplying fluid to said basin; a stand pipe at the center of said basin for receiving the overflow therefrom; a circular baffle plate surrounding said stand pipe, said baiile plate terminating above the bottom or" said basin so that said fluid may flow thereunder to reach said stand pipe;-and

. means for rotating said bafile plate.

2. A device for separating grit from solutions comprising: a circular basin; a settling chamber at the center of the bottom of said basin; means for supplying fluid to said basin; a stand pipe at the center of said basin for receiving the overflow from said basin; and a circular baflle plate sur- 5 rounding said stand pipe, said baffle plate terminating above the bottom of said basin so that said fluid may flow thereunder to reach said stand pipe, said stand pipe passing upwardly from said settling chamber into said basin; and a 10 circular plate surrounding said stand pipe and spaced therefrom, said plate forming a top for surrounding said stand pipe and spaced there- 2 from, said plate forming a top for said settling chamber; and means for rotating said bafile plate.

4; A grit separator comprising: an open topped basin; a conical bottom in said basin open at its center; a settling chamber below said open bottom; an effluent outlet in the wall of said settling chamber; a stand pipe extending from said outlet upwardly into said basin; and a cylindrical baflie plate supported in said basin about said standpipe and relatively close to the walls of said basin; and means for delivering influent through the wall of said basin and against said baille plate. 5. A grit separator comprising: an open topped basin; a conical bottom in said basin open at its 40 center; a settling chamber below said open bottom; an effluent outlet in the wall of said settling chamber; a stand pipe extending from said outlet upwardly into said basin; a cylindrical baffle plate supported in said basin about said 4 standpipe and relatively close to the walls of said basin; means for delivering influent through the wall of said basin and against said baffle plate; and means for rotating said baflle plate.

6. A grit separator comprising: an open topped basin; a conical bottom in said basin open at its center; a settling chamber below said open bottom; an effluent outlet in the wall of said settling chamber; a stand pipe extending from said outlet upwardly'into said basin; a cylindrical baflle 5' plate supported in said basin about said standpipe and relatively close to the Wallsof said basin; means for delivering influent through the wall of said basin and against said bafile plate; means for rotating said baffle plate; and paddles extending from saidbaffie plate into the space between the baflle plate and wall of said basin.

7. A grit separator comprising: an open topped basin; a conical bottom in said basin open at its center; a settling chamber below said open bottom; an efiluent outlet in the wall of said settling chamber; a stand pipe extending from said outlet upwardly into saidbasin; a cylindrical baffle supported in said basin about said standpipe and relatively close to the walls of said basin; means for delivering influent through the wall of said basin and against said baflle; and a conical plate surrounding said stand pipe and spaced therefrom, said plate forming a cover for said set- I tling chamber and a continuation of the bottom of said chamber.

8. A grit separator comprising: an open topped basin; a conical bottom in said basin open at its center; a settling chamber below said open bottom; an effluent outlet in the wall of said settling chamber; a stand pipe extending from said outlet upwardly into said basin; a cylindrical baflle supported in said basin about said standpipe and relatively close to the walls of said basin; means for delivering infiuent through the wall of said basin and against said baffle; a passage for receiving the efliuent from said basin, said passage terminating adjacent the wall thereof; and a conduit connecting the efliuent outlet with said passage.

9. A grit separator comprising: an open topped basin; a conical bottom in said basin open at its center; a settling chamber below said open bottom; an effluent outlet in the wall of said settling chamber; a stand pipe extending from said outlet upwardly into said basin; beams extending across said basin; a bearing supported by said beams; a shaft supported in said bearing and extending downwardly therefrom; spokes extending outwardly from said shaft; a cylindrical baflle plate suspended from said spokes in spaced relation with the wall of said basin and terminating above the bottom thereof; means for supplying fluid through the Wall of said chamber against said plate; and means for rotating said shaft so as to rotate said bafile plate.

10. A grit separator comprising: an open 5 topped basin; a conical bottom in said basin open at its center; a settling chamber below said open bottom; an eflluent outlet in the wall of said settling chamber; a stand pipe extending from said outlet upwardly into said basin; beams extending across said basin; a bearing supported by said beams; a shaft supported in said bearing and extending downwardly therefrom; spokes extending outwardly from said shaft; a cylindrical bafiie plate suspended from said spokes in spaced relation with the wall of said basin and terminating above the bottom thereof; means for supplying fluid through the wall of said chamber against said plate; means for rotating said shaft so as to rotate said bafile plate; and paddles extending outwardly from said bafiie plate into the space between said plate and said walls.

11. A grit separator comprising: a vertically suspended rotary cylindrical baffle plate; an overflow positioned within said baflle plate; paddles extending outwardly from said bafile plate; and means for rotating said plate about said overflow.

CARL H. NORDELL. 

